"I've been happy to just make it to this point, to the NFL," Brown said according to the Associated Press. "But once you get here, it's hard work and I realize that. It took me a while to mature and get to this point in my life where I've become a complete pro and I'm just happy that they recognized that, and had the confidence in me to extend this great deal."
The Texans had just $3.3 million remaining before the Brown extension, according to a source with knowledge of each team's available cap space, which means Barwin and Schaub might have to wait until after the season before having their contracts addressed.
General manager Rick Smith acknowledged that retaining Brown was a top priority.
"He's a young, ascending player," said Smith, according to The AP. "He's determined to being as good as he can be, and I think he's committed to being as good as there is in the league."
A 2008 first-round draft pick out of Virginia Tech, Brown has started 62 of a possible 66 regular and postseason games during his four-year career. Brown was suspended for four games during the 2010 season after violating the NFL's substance abuse policy.
The 6-foot-4, 320-pound Brown has emerged as one of the top left tackles in the NFL and was named second-team All-Pro by the Associated Press following the 2011 season.
UPDATE: The Texans have confirmed the extension, which, a source with knowledge of the talks told NFL.com and NFL Network reporter Ian Rapoport, is for six years and $53.4 million with $22.08 million guaranteed.